Release mechanism for safety ski bindings

ABSTRACT

A release mechanism for safety ski bindings activated by a magnetic release system and movable between a cocked and a release condition. In its release condition, the mechanism releases a ski binding from a closed to an open condition. The mechanism has a holding lever movable between a holding and a releasing position, with the holding lever abutting a connecting lever which, along with a handle lever and a release lever, forms a spring retaining mechanism. The release lever is spring biased from a cocked to a releasing condition.

BACKGROUND OF THE INVENTION

This invention relates to a release mechanism for safety ski bindingsfor amplifying the releasing force of a magnetic release system to alevel sufficient to achieve release of a safety ski binding from aclosed position to an open position, thus disengaging a ski boot fromthe ski.

For a skier's optimum safety and convenience, it is important that,while skiing, each ski boot is rigidly fixed with respect to the ski. Onthe other hand, in the event of an imminent fall it is important thatthe ski boot be disengaged from the ski to minimize possible injury tothe skier. To achieve these goals, a wide variety of safety ski bindingshave been developed for releasing a ski boot from a ski when the forceson the ski exceed a predetermined value.

Many ski bindings are entirely mechanical in nature. These mechanicalbindings, while useful, tend to be somewhat unpredictable. Although thebinding may be set to release when a predetermined force is applied,ice, snow, and dust may interfere with the binding's operation. Also,mechanical bindings often utilize mechanisms that latch the boot to theski at the heel and toe of the boot. Such a binding detects only thatcomponent of applied force that acts on the heel or toe portion of thebinding. This is adequate to achieve release when the skier falls eitherforward or backward, however, with twisting falls or with falls to theside, even though the total force may be sufficient to constitute adanger to the skier, the component of the force acting on the heel ortoe of the binding may be insufficient to achieve release of the skiboot from the ski.

In recent years, electronic ski bindings have been proposed to overcomesome of these disadvantages. Some of these bindings include sensors thatdetect not only the forces acting on the toe and heel portions of theski boot, but additionally, the forces acting on the sides of the skiboot, such as occur with twisting falls or falls to the side. Thesesensors are designed to generate electrical signals when release isappropriate. Examples of such bindings are disclosed in U.S. Pat. No.4,291,894 (D'Antonio, et al.), incorporated herein by reference.

While these improved ski bindings utilize an electronic system fordetecting forces on the ski, the physical release of the ski bootgenerally involves a mechanical system. Thus, it is necessary to designelectronic bindings so that the electrical signals will result inactuation of the mechanical ski boot release. To achieve this goal, aninterface between the electronic and mechanical components of the skibinding is necessary. The interface must be activated by the electronicsignals and, in turn, actuate the mechanical release system thatcontrols physical release of the ski boot from the ski. Examples of suchski bindings are disclosed in U.S. Pat. No. 4,130,296 (D'Antonio, etal.), incorporated herein by reference. In that reference, a solenoid isutilized as an interface, while magnetic release systems for this useare proposed in earlier referenced U.S. Pat. No. 4,291,894.

An improved magnetic release system is disclosed in U.S. Pat. No.4,484,761 (German Application No. P 31 28 185.0). This system utilizes arelease arm with a small mass relative to the mass of a permanent magnetand an electromagnet. The arm is spring biased towards an actuatingposition and is held in a non-actuating position, against the springforce, by a magnetic field induced by the permanent magnet. When skiboot release is appropriate, an electrical impulse from the electroniccomponent of the ski binding energizes the electromagnet, diminishing orcancelling the magnetic field induced by the permanent magnet. Therelease arm, no longer restrained in its non-actuating position by themagnetic field, moves under spring force to its actuating position inwhich the arm initiates ski boot release.

The above-described magnetic release system is advantageous for it ishighly efficient with resulting low energy consumption; this, in part,because it is necessary only to diminish or cancel the magnetic fieldinduced by a small permanent magnet, allowing spring force to move therelease arm. Also, the system provides a reduced possibility of faultyrelease due to the small mass of the release arm relative to the mass ofthe permanent magnet and the electromagnet. A consequence of achievingthese advantages is that the releasing force exerted by movement of therelease arm from its nonactuating to its actuating position isrelatively small; smaller, indeed, than the force necessary forreleasing the ski binding from a closed to an open position. Thus, toachieve release of the ski binding and consequent release of a ski bootfrom the ski, it is necessary to enhance the force exerted by therelease arm. This invention provides a convenient means of enhancing thereleasing force of a magnetic release system.

SUMMARY OF THE INVENTION

This invention provides a release mechanism which functions as a forceamplifier, movable between cocked and release conditions for translatingthe releasing force of a magnetic release system to a level sufficientto achieve release of a ski binding latching mechanism from its latchingcondition to its unlatching condition. In its unlatching position, thelatching mechanism releases a ski binding from its closed to its opencondition. A force amplifier according to this invention preferablycomprises a holding means for holding the release mechanism in itscocked condition; the holding means movable between a holding and areleasing position. The holding means in its holding position restrainsa retaining means in its retaining condition; wherein the retainingmeans retains a release means in its cocked position. A spring meansbiases the release means from a cocked to a releasing position.

Movement of the holding means to its releasing position results inmovement of the retaining means to a releasing condition. The springmeans then urges the release means from its cocked to its releasingposition. Movement of the release means to its releasing position urgesa latching means from a latching to an unlatching condition, releasingthe ski binding from its closed to its open condition; thus, releasingthe ski boot from the ski.

The spring means associated with a force amplifier according to thisinvention is stronger than the spring means associated with an efficientmagnetic release system as above described; with the former spring meansexerting a force sufficient to urge the latching means from a latchingto an unlatching condition. With this construction, it is possible forthe relatively small releasing force of an efficient magnetic releasesystem to initiate mechanical release of a ski binding from a closed toan open condition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A force amplifier according to this invention, in its cockedcondition, showing a magnetic release system in its non-actuatingposition and a latching means in its latched condition.

FIG. 2 A force amplifier according to this invention in its releasingposition showing a latching means in its unlatching condition.

FIG. 3 A modified construction of a force amplifier according to FIG. 1and FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning to the drawings, FIG. 1 illustrates a preferred embodiment of aforce enhancer according to this invention in its cocked condition ascomprising a holding lever 18 pivotally mounted on an axle 24; saidholding lever 18 biased in a clockwise direction, as shown by arrow 19,about axle 24 by a spring (not shown). (All references to directionssuch as clockwise, counterclockwise, left and right refer to directionsas illustrated in FIG. 1 and FIG. 2). One arm of lever 18 contacts astop 20 which is preferably a soft iron post associated with a magneticrelease system. The magnetic release system is shown as comprising amagnet 1, a release arm 2, a release spring 3 and stop 20. Magnet 1 andspring 3 are mounted on a fixed part 4 of a safety ski binding (notshown). FIG. 1 illustrates release arm 2 in its non-actuating position.

Abutment end 29 of lever 18 abuts a connecting lever 15, whichconnecting lever 15 is pivotally mounted on an axle 16 and is springbiased in a counterclockwise direction, as shown by arrow 17, about axle16. Connecting lever 15 has a groove 14 which contacts a free end 13 ofa handle lever 11. Lever 11 is pivotally mounted on an axle 12.

A release lever 8, pivotally mounted on an axle 9, has a free end 10positioned between an abutment piece 25, part of handle lever 11, and apiston 21. Piston 21 is slideably mounted in an opening in fixed part 4and is spring biased to the left by a tension spring 22, with tensionspring 22 positioned between fixed part 4 and an annular shoulder 26,part of piston 21. Piston 21 biases release lever 8 in acounterclockwise direction causing lever 8 to contact abutment piece 25,thus retaining lever 8 in its cocked position. Connecting arm 15, handlelever 11 and free end 10 comprise a spring retaining means. FIG. 1illustrates spring 22 in its compressed position.

Release lever 8 is connected to a latching lever 5 by means of a peg 7.Latching lever 5 is slideably mounted in an opening 27 in a fixed part 6of the safety ski binding. FIG. 1 illustrates latching lever 5 in itslatching condition. A leaf spring 23 is attached to release lever 8 andcontacts connecting lever 15, biasing lever 15 in a clockwise directionabout axle 16 and against the spring force in arrow direction 17. Thepurpose of spring 23 will be discussed further below. Axles 9, 12, 16and 24 are all parallel to each other and are fixably mounted to a fixedpart (not shown) of the safety ski binding.

When release is appropriate, an electrical impulse is received from theelectronic component of a safety ski binding. As described earlier, thisimpulse energizes an electromagnet in the magnetic release system 1, 2,3, 20 which reduces or cancels the magnetic field induced by a permanentmagnet. Release arm 2 then rotates in a counterclockwise direction underthe influence of release spring 3 about an edge 28 of electromagnet 1 toits actuating position (not shown).

Movement of a force amplifier according to this embodiment of theinvention from its cocked position (FIG. 1) to its releasing position(FIG. 2) occurs in the following manner. As release arm 2 rotates fromits non-actuating to its actuating position, it contacts holding lever18, urging lever 18 in a counterclockwise direction about axle 24against the spring force in arrow direction 19. In this manner, abutmentpiece 29 is moved from a position in which it abuts connection lever 15.Connecting lever 15 then rotates in a counterclockwise direction aboutaxle 16 under the influence of the spring force in arrow direction 17.As it rotates, connecting arm 15 urges free end 13 of handle lever 11 tothe left which, in turn, rotates lever 11 in a clockwise direction aboutaxle 12. The rotation of connecting arm 15 also results in its lowerportion abutting release arm 2 to urge it against magnet 1 to close theend of magnet 1 against possibly deleterious dirt. This further rotatesabutment end 25 of lever 11 to a position in which it no longer abutsfree end 10 of release lever 8. Free from the restraint of abutmentpiece 25, piston 21 and free end 10 are forced to the left under theinfluence of spring 22, thus rotating release lever 8 in acounterclockwise direction about axle 9.

The rotation of release lever 8 urges latching lever 5 to the left, fromits latching position to its unlatching position. With latching lever 5in its unlatching position, the ski binding is released from its closedcondition, in which it holds a ski boot rigidly to the ski, to its opencondition in which the ski boot is released from the ski. The positionsof all components of a force amplifier according to this preferredembodiment of the invention in its releasing position are illustrated inFIG. 2.

Release arm 2 of the magnetic release system returns to itsnon-actuating position under the influence of the magnetic field inducedby the permanent magnet, for that field is only momentarily diminishedor cancelled by the current surge through the electromagnet. Holdinglever 18 then returns to its original position under spring influence inspring direction 19. However, when the force amplifier is in itsreleasing position (FIG. 2), lever 18 does not abut connecting lever 15which has moved to its release position in which it contacts release arm2. Free end 10 of release lever 8 rests against fixed part 6 of thesafety ski binding.

The return of the above-described force amplifier to its cocked positionrequires a transition from the position illustrated in FIG. 2 to theposition illustrated in FIG. 1. This is accomplished through applyingpressure to latching lever 5, urging it to the right. This urges releaselever 8 in a clockwise direction and piston 21 to the right, thuscompressing spring 22. As lever 8 rotates, leaf spring 23 contactsconnecting lever 15 rotating it in a clockwise direction against thespring force in spring direction 17. Free end 13 is moved to the rightand abutment end 25 is rotated into a position in which it again abutsfree end 10. As lever 15 rotates, it urges lever 18 in acounterclockwise direction. Under spring influence in spring direction19, lever 18 promptly returns to its holding position when lever 15 hasrotated beyond abutment end 29 of lever 18. Abutment end 29 then abutslever 15 and the force enhancer is returned to its cocked position.

Levers 8, 11, 15 and 18 are preferably formed of sheet metal or othersuitable material that provides considerable strength combined withsimple construction, such as certain plastics. Latching lever 5 ispreferably constructed such that movement of lever 5 to the left resultsdirectly in release of the ski binding. This is not illustrated in thedrawings, but results in simplification of the binding.

An additional advantage of this construction of a force amplifieraccording to this invention is that the vector direction of the force byrelease spring 22 is the same as the vector direction necessary toachieve unlatching of latching lever 5, thus the force of spring 22 isutilized with little loss. Also, a leverage advantage is attained byconstructing connecting lever 15 as a two-armed lever with one armlonger than the other arm; the short arm located between axle 16 andhandle lever 11 and the long arm positioned between axle 16 and holdinglever 18.

FIG. 3 illustrates a modified construction of a force amplifieraccording to FIG. 1 and FIG. 2. In FIG. 3, holding lever 18' replacesholding lever 18 and connecting lever 15' replaces lever 15. Lever 18'is notched so that, when the force amplifier is cocked, lever 18' isretained in its holding position by lever 15' rather than by stop 20.

Considerable force is exerted on the ski binding biasing it towards itsopen position. This creates a high frictional force on latching lever 5and the necessity for a relatively high force to counter the frictionalforce and urge lever 5 to its unlatching position. Spring 22 is capableof exerting this force, while itself being activated by the relativelysmall force of release arm 2. This is possible because the leveragingarrangement of levers 8, 11 and 15 results in relatively smallfrictional force between abutment end 29 and connecting lever 15, and itis this smaller frictional force against which release arm 2 must act.The further importance of leaf spring 23 becomes apparent here also, forspring 23 biases connecting lever 15 in a clockwise direction, thusfurther minimizing the frictional force between abutment end 29 andconnecting lever 15. In this manner, the force necessary to rotate lever18 to its release position is reduced to a point where it is readilyactivated by movement of release arm 2 to its actuating position.

Through use of force amplifier according to this invention, it ispossible to retain the advantages of a small, lightweight magneticrelease system, such as the important advantage of minimal energyrequirements, while attaining a releasing force sufficient to achievereliable release of the ski binding. A force amplifier according to thisinvention may be quite small and lightweight. By constructing andmounting holding lever 18 in such manner that axle 24 is located closeto lever 18's center of gravity, optimal safety against faulty releasefrom jarring or shocks is also achieved.

While in its preferred form, release of the mechanism is effected uponthe generation of an electrical signal to effect a reduction in themagnetic attraction of arm 2, it is within the scope of the invention toeffect release upon the attraction of the arm towards the magnet, with aconcomitant variation in the construction of the foregoing mechanism.

This invention has been described in detail with particular emphasis onthe preferred embodiments, however it should be understood that thereare variations and modifications within the scope and spirit of theinvention.

I claim:
 1. A release mechanism for safety ski bindings which generaterelease signals to effect unlatching of the binding, said mechanismbeing movable between a cocked and a releasing condition, and saidmechanism comprising;release means for releasing a ski binding latchingmechanism from a latching to an unlatching condition, said release meansincluding a release lever movable between a cocked position and areleasing position for releasing the binding to the unlatchingcondition; biasing means for biasing said release means from a cocked toa releasing position, said biasing means including drive means movablebetween a cocked position and a releasing position for driving saidrelease lever to the releasing position of said release lever, andspring means for urging said drive means to the releasing position ofsaid drive means, said drive means assuming the releasing position inresponse to the generation of release signals; retaining means forretaining said release lever in its cocked position; said retainingmeans movable between a retaining and a releasing condition; holdingmeans for holding said retaining means in its retaining condition; saidholding means being movable between a holding and a releasing position;said holding means moving to the releasing position in response to arelease signal from the binding, to release said retaining means to itsreleasing condition enabling said release means to release the latchingmechanism.
 2. A release mechanism according to claim 1 wherein saidretaining means comprises a connecting lever and a handle lever, saidhandle lever being movable between a cocked position for blocking saidrelease means against releasing the latching mechanism and a releasingposition for releasing said release means, and said connecting leverbeing movable between a cocked position for holding said handle lever inits cocked position and a releasing position for releasing said handlelever, said connecting lever moving from its cocked position to itsreleasing position in response to movement of said holding means fromits holding to its releasing positions.
 3. The invention according toclaim 2, further comprising means for biasing said connecting lever fromits cocked position to its releasing position.
 4. The inventionaccording to claim 2 or claim 3, further comprising means for biasingsaid connecting lever from its releasing position to its cockedposition.
 5. A release mechanism according to claim 2, wherein saidconnecting lever is pivotally mounted on an axle and comprising a shortarm positioned between said handle lever and said axle and a long armpositioned between said holding lever and said axle.
 6. A releasemechanism according to claim 2, wherein said biasing means moves saidrelease lever to its releasing position in response to movement of saidhandle lever to its releasing position.
 7. A release mechanism accordingto claim 6, wherein said release means further comprises a latchinglever movable in a linear path in response to movement to said releaselever.
 8. A release mechanism according to claim 1, wherein said pistonis movable in a linear path.
 9. A release mechanism according to claim1, wherein the ski binding comprises an electromagnet for generatingsignals to effect actuation of the release mechanism to the releasingcondition; and wherein said release mechanism comprises a fixed stopassociated with the electromagnet, and said holding means comprises aholding lever movable between a holding position for holding saidconnecting means in its cocked condition, and a releasing position forreleasing said connecting means to the releasing condition in responseto a release signal from the binding.
 10. A release mechanism accordingto claim 9, further comprising a release arm for moving said holdinglever to the releasing position in response to a release signal from thebinding.
 11. A release mechanism according to claim 1, wherein saidholding means comprises a holding lever movable between a holdingposition for holding said retaining means in its cocked condition, and areleasing position for releasing said connecting means to the releasingcondition in response to a release signal from the binding.